The federal government has awarded New Jersey's largest wastewater-treatment plant more than $260 million in post-Hurricane Sandy aid to fortify the facility against future storm damage.

The Passaic Valley Sewerage Commission’s 152-acre plant in Newark was crippled during Sandy as a 12-foot storm surge pushed across the property, flooding critical infrastructure. Power outages left key pumping stations inoperable for 48 hours, forcing the plant to dump 840 million gallons of untreated sewage into Newark Bay to prevent raw sewage from backing up into thousands of homes, officials said.

Gov. Chris Christie and federal lawmakers announced the roughly $260 million grant from the Federal Emergency Management Agency last week. The grant, they said, was the largest ever awarded through the federal agency's public assistance program.

The money will help construct a flood-protection system at the facility and fund a microgrid project, which will allow the plant to continue to operate when a larger power outage occurs.

The overall mitigation effort is expected to cost nearly $290 million and take between five to seven years to complete. The FEMA grant will cover 90 percent of the project's costs and the Passaic Valley Sewerage Commission will pick up the remaining 10 percent.

The Newark facility, which is the fifth largest in the nation, processes 25 percent of New Jersey’s waste and 15 percent of New York City’s, according to officials.

FEMA has already awarded roughly $72 million to the commission for other recovery projects.

“Investing in the protection of critical facilities is essential to building New Jersey back better and stronger after Sandy,” Christie said in a statement.